services: Define '%loopback-static-networking'.

* gnu/services/base.scm (%loopback-static-networking): New variable.
(%base-services): Use it.
* gnu/system/hurd.scm (%base-services/hurd): Use it.
* gnu/system/install.scm (%installation-services): Use it.
* doc/guix.texi (Networking Setup): Document it.

1 files changed, 1 insertions, 7 deletions

diff --git a/gnu/system/install.scm b/gnu/system/install.scm
index bdfe5801453..073d7df1dbb 100644
--- a/gnu/system/install.scm
+++ b/gnu/system/install.scm
@@ -408,13 +408,7 @@ Access documentation at any time by pressing Alt-F2.\x1b[0m
 
           ;; Loopback device, needed by OpenSSH notably.
           (service static-networking-service-type
-                   (list (static-networking
-                          (addresses
-                           (list (network-address
-                                  (device "lo")
-                                  (value "127.0.0.1"))))
-                          (requirement '())
-                          (provision '(loopback)))))
+                   (list %loopback-static-networking))
 
           (service wpa-supplicant-service-type)
           (dbus-service)